Doughnuts and coffee are for cops working after midnight. The donut shops are the only place open, and the coffee is necessary to keep you awake until quitting time. Back when I didn't have enough seniority to keep from working graveyard shift, I ate a few Dunkin' Donuts. I quit eating 'em when they discontinued the whole wheat donuts. Old hippie habits die hard.

Ranger Steve is right. Most of the cops these days are trying to stay healthy. Some agencies offer incentive pay for a certain level of physical fitness.